Question

An 81-year-old man and avid reader had a mild stroke from which he eventually recovered. He did have some residual signs and symptoms, however, such as:

- right-sided homonymous hemianopia (i.e. loss of vision on the right half of the visual field in each eye)

- alexia ("dyslexia"), the inability to read, which greatly frustrated this man

- loss of sensation on the skin on the right side of the body

Questions:

1. What cerebral artery was blocked during his stroke? (Be Specific.)

2. Why was this man unable to see the right half of his field of vision? Was there something wrong with his eyes?

3. If this man could still see the left half of his visual field, why did he still have difficulty reading? In your answer, be sure to mention all of the relevant pathways down which nerve impulses must travel for him to be able to read.

Thanks

Answer 1

1. Middle cerebral artery was blocked during his stroke in left hemisphere of the brain causing right side sensor loss,dyslexia and right-sided homonymous hemianopia.

2.Injury in the left hemisphere of the brain affects the optic nerves which causes the man to loss the right half of his field of vision.

3. The stroke caused the disconnection of the visual assocation cortices from the temporoparietal cortex which is dominantly related with language.The visual association cortices no longer able to send signal to the optic nerve and downstream optic chiasm and can't form the visual reflections. This disconnection causing the  difficulty in reading.